package leetcode.editor.cn;

//////设计一个支持 push ，pop ，top 操作，并能在常数时间内检索到最小元素的栈。 
//////
////// 实现 MinStack 类: 
//////
////// 
////// MinStack() 初始化堆栈对象。 
////// void push(int val) 将元素val推入堆栈。 
////// void pop() 删除堆栈顶部的元素。 
////// int top() 获取堆栈顶部的元素。 
////// int getMin() 获取堆栈中的最小元素。 
////// 
//////
////// 
//////
////// 示例 1: 
//////
////// 
//////输入：
//////["MinStack","push","push","push","getMin","pop","top","getMin"]
//////[[],[-2],[0],[-3],[],[],[],[]]
//////
//////输出：
//////[null,null,null,null,-3,null,0,-2]
//////
//////解释：
//////MinStack minStack = new MinStack();
//////minStack.push(-2);
//////minStack.push(0);
//////minStack.push(-3);
//////minStack.getMin(); --> 返回 -3.
//////minStack.pop();
//////minStack.top(); --> 返回 0.
//////minStack.getMin(); --> 返回 -2.
////// 
//////
////// 
//////
////// 提示： 
//////
////// 
////// -2³¹ <= val <= 2³¹ - 1 
////// pop、top 和 getMin 操作总是在 非空栈 上调用 
////// push, pop, top, and getMin最多被调用 3 * 10⁴ 次 
////// 
////// Related Topics 栈 设计 👍 1369 👎 0
////
//

import java.util.Stack;

//Java：【155】- 最小栈
public class LeetCode_155_MinStack{
    public static void main(String[] args) {
        MinStack solution = new LeetCode_155_MinStack().new MinStack();
        // TO TEST
    }
    
    //leetcode submit region begin(Prohibit modification and deletion)
class MinStack {
    private Stack<Integer> stack;
    private Stack<Integer> minStack;
    public MinStack() {
        this.stack = new Stack<>();
        this.minStack = new Stack<>();
    }
    
    public void push(int val) {
        stack.push(val);
        if(minStack.isEmpty() || minStack.peek()>=val){
            minStack.push(val);
        }
    }
    
    public void pop() {
        int pop = stack.pop();
        if(minStack.peek()==pop){
            minStack.pop();
        }
    }
    
    public int top() {
        return stack.peek();
    }
    
    public int getMin() {
        return minStack.peek();
    }
}

/**
 * Your MinStack object will be instantiated and called as such:
 * MinStack obj = new MinStack();
 * obj.push(val);
 * obj.pop();
 * int param_3 = obj.top();
 * int param_4 = obj.getMin();
 */
//leetcode submit region end(Prohibit modification and deletion)

}